为什么我的听众不……在听？
Why is my listener not.. Listening?
我是 Java 和 OpenGL 的新手。
我有一个监听器，我想弄清楚为什么它不起作用？当我按下一个键时，绝对没有任何反应。我指的听众是：
@Override
public void keyTyped(KeyEvent e)
{
// TODO Auto-generated method stub
char key= e.getKeyChar();
System.out.printf("Key typed: %c\n", key);
}
这是我的文件。
HelloOpenGL.java
package helloOpenGL;
/*************************************************************************************
* IMPORTS
**************************************************************************************/
import java.awt.BorderLayout;
import java.awt.Frame;
import com.jogamp.opengl.GLCapabilities;
import com.jogamp.opengl.awt.GLCanvas;
import com.jogamp.opengl.util.Animator;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
/*************************************************************************************
* Class HelloOpenGL
**************************************************************************************/
public class HelloOpenGL extends Frame
{
// Animator? Unneeded??
static Animator anim = null;
/*************************************************************************************
* setupJOGL
*
* Method that sets up Java openGL??
**************************************************************************************/
private void setupJOGL()
{
GLCapabilities caps = new GLCapabilities(null);
caps.setDoubleBuffered(true);
caps.setHardwareAccelerated(true);
GLCanvas canvas = new GLCanvas(caps);
add(canvas);
JoglEventListener jgl = new JoglEventListener();
canvas.addGLEventListener(jgl);
canvas.addKeyListener(jgl);
//anim = new Animator(canvas);
//anim.start();
}
/*************************************************************************************
* HelloOpenGL Constructor ?
**************************************************************************************/
public HelloOpenGL()
{
super("test");
setLayout(new BorderLayout());
// To close window
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
setSize(600, 600);
setLocation(40, 40);
setVisible(true);
// Call setupJOGL
setupJOGL();
}
public static void main(String[] args)
{
// Instantiate object
HelloOpenGL demo = new HelloOpenGL();
// Show it?
demo.setVisible(true);
}
}
class MyWin extends WindowAdapter
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
JoglEventListener.java
package helloOpenGL;
/*************************************************************************************
* IMPORTS
**************************************************************************************/
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import com.jogamp.opengl.*;
import com.jogamp.opengl.glu.GLU;
/*************************************************************************************
* JoglEventListener
**************************************************************************************/
public class JoglEventListener implements GLEventListener, KeyListener
{
float[] vertices={5.97994f, -0.085086f, -0.010798f,
5.97994f, 10.0043f, -0.010798f,
7.99077f, 10.0043f, -0.010798f,
7.99077f, 11.3449f, -0.010798f,
-0.405339f, 11.3449f, -0.010798f,
-0.405339f, 9.98083f, -0.010798f,
1.65252f, 9.98083f, -0.010798f,
1.65252f, 0.549879f, -0.010798f,
-0.722839f, 0.549879f, -0.010798f,
-0.722839f, -1.69612f, -0.010798f,
2.6168f, -1.69612f, -0.010798f,
-7.24925f, 0.42055f, -0.010798f,
-9.35415f, 0.42055f, -0.010798f,
-9.35415f, 10.0043f, -0.010798f,
-7.37859f, 10.0043f, -0.010798f,
-7.37859f, 11.3802f, -0.010798f,
-15.8217f, 11.3802f, -0.010798f,
-15.8217f, 9.99258f, -0.010798f,
-13.8109f, 9.99258f, -0.010798f,
-13.8109f, -0.061591f, -0.010798f,
-10.2361f, -1.73139f, -0.010798f,
-7.26099f, -1.73139f, -0.010798f,
-6.1909f, 0.855631f, -0.010798f,
-8.11942f, 0.855631f, -0.010798f,
-8.11942f, 2.31379f, -0.010798f,
0.217914f, 2.31379f, -0.010798f,
0.217914f, 0.926204f, -0.010798f,
-1.73415f, 0.926204f, -0.010798f,
-1.73415f, -4.10675f, -0.010798f,
9.23724f, 0.937952f, -0.010798f,
7.26169f, 0.937952f, -0.010798f,
7.26169f, 2.38434f, -0.010798f,
15.6696f, 2.38434f, -0.010798f,
15.6696f, 1.00851f, -0.010798f,
14.964f, 1.00851f, -0.010798f,
7.75558f, -2.44873f, -0.010798f,
14.4231f, -9.36318f, -0.010798f,
16.0576f, -9.36318f, -0.010798f,
16.0576f, -10.6685f, -0.010798f,
7.62625f, -10.6685f, -0.010798f,
7.62625f, -9.33965f, -0.010798f,
9.67236f, -9.33965f, -0.010798f,
4.49827f, -3.90687f, -0.010798f,
-1.35784f, -6.59973f, -0.010798f,
-1.35784f, -9.3279f, -0.010798f,
0.217914f, -9.3279f, -0.010798f,
0.217914f, -10.6919f, -0.010798f,
-8.22526f, -10.6919f, -0.010798f,
-8.22526f, -9.32786f, -0.010798f,
-6.20266f, -9.32786f, -0.010798f};
int[] indices={3, 2, 3, 1,
3, 1, 3, 6,
3, 1, 6, 10,
3, 10, 6, 7,
3, 10, 7, 8,
3, 4, 5, 6,
3, 4, 6, 3,
3, 10, 8, 9,
3, 1, 10, 0,
3, 13, 14, 15,
3, 13, 15, 18,
3, 13, 18, 20,
3, 13, 20, 12,
3, 16, 17, 18,
3, 16, 18, 15,
3, 12, 20, 21,
3, 12, 21, 11,
3, 20, 18, 19,
3, 49, 22, 44,
3, 44, 22, 28,
3, 44, 28, 43,
3, 43, 28, 29,
3, 43, 29, 42,
3, 42, 29, 35,
3, 42, 35, 41,
3, 41, 35, 36,
3, 41, 36, 38,
3, 38, 36, 37,
3, 39, 40, 41,
3, 39, 41, 38,
3, 29, 30, 32,
3, 29, 32, 34,
3, 29, 34, 35,
3, 46, 47, 49,
3, 46, 49, 44,
3, 46, 44, 45,
3, 22, 23, 25,
3, 22, 25, 27,
3, 22, 27, 28,
3, 25, 23, 24,
3, 27, 25, 26,
3, 49, 47, 48,
3, 32, 30, 31,
3, 34, 32, 33};
float backrgb[] = new float[4];
float rot;
// Instantiate GLU thing?
private GLU glu = new GLU();
/*************************************************************************************
* displayChanged
* What does this do?
**************************************************************************************/
public void displayChanged(GLAutoDrawable gLDrawable,
boolean modeChanged, boolean deviceChanged)
{
// Function that does nothing?
}
/** Called by the drawable immediately after the OpenGL context is
* initialized for the first time. Can be used to perform one-time OpenGL
* initialization such as setup of lights and display lists.
* @param gLDrawable The GLAutoDrawable object.
*/
/*************************************************************************************
* init
**************************************************************************************/
public void init(GLAutoDrawable gLDrawable)
{
GL2 gl = gLDrawable.getGL().getGL2();
//gl.glShadeModel(GL.GL_LINE_SMOOTH); // Enable Smooth Shading
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background
gl.glClearDepth(1.0f); // Depth Buffer Setup
gl.glEnable(GL.GL_DEPTH_TEST); // Enables Depth Testing
gl.glDepthFunc(GL.GL_LEQUAL); // The Type Of Depth Testing To Do
// Really Nice Perspective Calculations
//gl.glHint(GL.GL_PERSPECTIVE_CORRECTION_HINT, GL.GL_NICEST);
}
public void reshape(GLAutoDrawable gLDrawable, int x, int y, int width,
int height)
{
final GL2 gl = gLDrawable.getGL().getGL2();
if (height <= 0) // avoid a divide by zero error!
height = 1;
final float h = (float) width / (float) height;
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL2.GL_PROJECTION);
gl.glLoadIdentity();
glu.gluPerspective(45.0f, h, 1.0, 200.0);
gl.glMatrixMode(GL2.GL_MODELVIEW);
gl.glLoadIdentity();
gl.glTranslatef(0.0f, 0.0f, -40.0f);
}
@Override
public void display(GLAutoDrawable gLDrawable)
{
// TODO Auto-generated method stub
final GL2 gl = gLDrawable.getGL().getGL2();
gl.glClearColor(backrgb[0], 0, 1, 1);
gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
backrgb[0]+=0.0005;
if (backrgb[0]> 1) backrgb[0] = 0;
// DRAW STUFF IN THIS FUNCTION
}
@Override
public void dispose(GLAutoDrawable arg0)
{
// TODO Auto-generated method stub
}
@Override
public void keyTyped(KeyEvent e)
{
// TODO Auto-generated method stub
char key= e.getKeyChar();
System.out.printf("Key typed: %c\n", key);
}
@Override
public void keyPressed(KeyEvent e)
{
// TODO Auto-generated method stub
}
@Override
public void keyReleased(KeyEvent e)
{
// TODO Auto-generated method stub
}
/*
public void init(GLDrawable gLDrawable) {
final GL gl = glDrawable.getGL();
final GLU glu = glDrawable.getGLU();
gl.glMatrixMode(GL.GL_PROJECTION);
gl.glLoadIdentity();
glu.gluOrtho2D(-1.0f, 1.0f, -1.0f, 1.0f); // drawing square
gl.glMatrixMode(GL.GL_MODELVIEW);
gl.glLoadIdentity();
}*/
}
基本上，当我按下键盘上的键时，由于某种原因，"key typed" 永远不会输出，就好像它没有在听一样。我确定我的错误出在某个微不足道的地方，但我不确定它在哪里？
您需要确保 canvas 具有焦点，以便在那里接收输入事件。我无法从代码量中判断哪个 GUI 元素接收输入事件。也可以将侦听器添加到显示的框架和其他元素中。或者将焦点明确设置到 canvas（并确保它停留在那里）。
使用的方法叫JComponent.requestFocus（当然是API) and needs to be called after the elements are displayed
必须将 key listener 添加到框架 (canvas)。我会将 HelloOpenGL class 扩展为 Frame，如下所示：
public class HelloOpenGL extends Frame implements KeyListener{
public HelloOpenGL(){
addKeyListener(this); //this statement is missing from your code
setFocusable(true);
...
}
...
//Override KeyListener interface methods in this class
}
所以我会在 HelloOpenGL class 本身中进行关键事件处理，因为它是代表框架的那个，还要记住 @Andy Turner 所说的。我以这种方式尝试了一个程序，在我的情况下效果很好。
我是 Java 和 OpenGL 的新手。
我有一个监听器，我想弄清楚为什么它不起作用？当我按下一个键时，绝对没有任何反应。我指的听众是：
@Override
public void keyTyped(KeyEvent e)
{
// TODO Auto-generated method stub
char key= e.getKeyChar();
System.out.printf("Key typed: %c\n", key);
}
这是我的文件。
HelloOpenGL.java
package helloOpenGL;
/*************************************************************************************
* IMPORTS
**************************************************************************************/
import java.awt.BorderLayout;
import java.awt.Frame;
import com.jogamp.opengl.GLCapabilities;
import com.jogamp.opengl.awt.GLCanvas;
import com.jogamp.opengl.util.Animator;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
/*************************************************************************************
* Class HelloOpenGL
**************************************************************************************/
public class HelloOpenGL extends Frame
{
// Animator? Unneeded??
static Animator anim = null;
/*************************************************************************************
* setupJOGL
*
* Method that sets up Java openGL??
**************************************************************************************/
private void setupJOGL()
{
GLCapabilities caps = new GLCapabilities(null);
caps.setDoubleBuffered(true);
caps.setHardwareAccelerated(true);
GLCanvas canvas = new GLCanvas(caps);
add(canvas);
JoglEventListener jgl = new JoglEventListener();
canvas.addGLEventListener(jgl);
canvas.addKeyListener(jgl);
//anim = new Animator(canvas);
//anim.start();
}
/*************************************************************************************
* HelloOpenGL Constructor ?
**************************************************************************************/
public HelloOpenGL()
{
super("test");
setLayout(new BorderLayout());
// To close window
addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
setSize(600, 600);
setLocation(40, 40);
setVisible(true);
// Call setupJOGL
setupJOGL();
}
public static void main(String[] args)
{
// Instantiate object
HelloOpenGL demo = new HelloOpenGL();
// Show it?
demo.setVisible(true);
}
}
class MyWin extends WindowAdapter
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
JoglEventListener.java
package helloOpenGL;
/*************************************************************************************
* IMPORTS
**************************************************************************************/
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import com.jogamp.opengl.*;
import com.jogamp.opengl.glu.GLU;
/*************************************************************************************
* JoglEventListener
**************************************************************************************/
public class JoglEventListener implements GLEventListener, KeyListener
{
float[] vertices={5.97994f, -0.085086f, -0.010798f,
5.97994f, 10.0043f, -0.010798f,
7.99077f, 10.0043f, -0.010798f,
7.99077f, 11.3449f, -0.010798f,
-0.405339f, 11.3449f, -0.010798f,
-0.405339f, 9.98083f, -0.010798f,
1.65252f, 9.98083f, -0.010798f,
1.65252f, 0.549879f, -0.010798f,
-0.722839f, 0.549879f, -0.010798f,
-0.722839f, -1.69612f, -0.010798f,
2.6168f, -1.69612f, -0.010798f,
-7.24925f, 0.42055f, -0.010798f,
-9.35415f, 0.42055f, -0.010798f,
-9.35415f, 10.0043f, -0.010798f,
-7.37859f, 10.0043f, -0.010798f,
-7.37859f, 11.3802f, -0.010798f,
-15.8217f, 11.3802f, -0.010798f,
-15.8217f, 9.99258f, -0.010798f,
-13.8109f, 9.99258f, -0.010798f,
-13.8109f, -0.061591f, -0.010798f,
-10.2361f, -1.73139f, -0.010798f,
-7.26099f, -1.73139f, -0.010798f,
-6.1909f, 0.855631f, -0.010798f,
-8.11942f, 0.855631f, -0.010798f,
-8.11942f, 2.31379f, -0.010798f,
0.217914f, 2.31379f, -0.010798f,
0.217914f, 0.926204f, -0.010798f,
-1.73415f, 0.926204f, -0.010798f,
-1.73415f, -4.10675f, -0.010798f,
9.23724f, 0.937952f, -0.010798f,
7.26169f, 0.937952f, -0.010798f,
7.26169f, 2.38434f, -0.010798f,
15.6696f, 2.38434f, -0.010798f,
15.6696f, 1.00851f, -0.010798f,
14.964f, 1.00851f, -0.010798f,
7.75558f, -2.44873f, -0.010798f,
14.4231f, -9.36318f, -0.010798f,
16.0576f, -9.36318f, -0.010798f,
16.0576f, -10.6685f, -0.010798f,
7.62625f, -10.6685f, -0.010798f,
7.62625f, -9.33965f, -0.010798f,
9.67236f, -9.33965f, -0.010798f,
4.49827f, -3.90687f, -0.010798f,
-1.35784f, -6.59973f, -0.010798f,
-1.35784f, -9.3279f, -0.010798f,
0.217914f, -9.3279f, -0.010798f,
0.217914f, -10.6919f, -0.010798f,
-8.22526f, -10.6919f, -0.010798f,
-8.22526f, -9.32786f, -0.010798f,
-6.20266f, -9.32786f, -0.010798f};
int[] indices={3, 2, 3, 1,
3, 1, 3, 6,
3, 1, 6, 10,
3, 10, 6, 7,
3, 10, 7, 8,
3, 4, 5, 6,
3, 4, 6, 3,
3, 10, 8, 9,
3, 1, 10, 0,
3, 13, 14, 15,
3, 13, 15, 18,
3, 13, 18, 20,
3, 13, 20, 12,
3, 16, 17, 18,
3, 16, 18, 15,
3, 12, 20, 21,
3, 12, 21, 11,
3, 20, 18, 19,
3, 49, 22, 44,
3, 44, 22, 28,
3, 44, 28, 43,
3, 43, 28, 29,
3, 43, 29, 42,
3, 42, 29, 35,
3, 42, 35, 41,
3, 41, 35, 36,
3, 41, 36, 38,
3, 38, 36, 37,
3, 39, 40, 41,
3, 39, 41, 38,
3, 29, 30, 32,
3, 29, 32, 34,
3, 29, 34, 35,
3, 46, 47, 49,
3, 46, 49, 44,
3, 46, 44, 45,
3, 22, 23, 25,
3, 22, 25, 27,
3, 22, 27, 28,
3, 25, 23, 24,
3, 27, 25, 26,
3, 49, 47, 48,
3, 32, 30, 31,
3, 34, 32, 33};
float backrgb[] = new float[4];
float rot;
// Instantiate GLU thing?
private GLU glu = new GLU();
/*************************************************************************************
* displayChanged
* What does this do?
**************************************************************************************/
public void displayChanged(GLAutoDrawable gLDrawable,
boolean modeChanged, boolean deviceChanged)
{
// Function that does nothing?
}
/** Called by the drawable immediately after the OpenGL context is
* initialized for the first time. Can be used to perform one-time OpenGL
* initialization such as setup of lights and display lists.
* @param gLDrawable The GLAutoDrawable object.
*/
/*************************************************************************************
* init
**************************************************************************************/
public void init(GLAutoDrawable gLDrawable)
{
GL2 gl = gLDrawable.getGL().getGL2();
//gl.glShadeModel(GL.GL_LINE_SMOOTH); // Enable Smooth Shading
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background
gl.glClearDepth(1.0f); // Depth Buffer Setup
gl.glEnable(GL.GL_DEPTH_TEST); // Enables Depth Testing
gl.glDepthFunc(GL.GL_LEQUAL); // The Type Of Depth Testing To Do
// Really Nice Perspective Calculations
//gl.glHint(GL.GL_PERSPECTIVE_CORRECTION_HINT, GL.GL_NICEST);
}
public void reshape(GLAutoDrawable gLDrawable, int x, int y, int width,
int height)
{
final GL2 gl = gLDrawable.getGL().getGL2();
if (height <= 0) // avoid a divide by zero error!
height = 1;
final float h = (float) width / (float) height;
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL2.GL_PROJECTION);
gl.glLoadIdentity();
glu.gluPerspective(45.0f, h, 1.0, 200.0);
gl.glMatrixMode(GL2.GL_MODELVIEW);
gl.glLoadIdentity();
gl.glTranslatef(0.0f, 0.0f, -40.0f);
}
@Override
public void display(GLAutoDrawable gLDrawable)
{
// TODO Auto-generated method stub
final GL2 gl = gLDrawable.getGL().getGL2();
gl.glClearColor(backrgb[0], 0, 1, 1);
gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
backrgb[0]+=0.0005;
if (backrgb[0]> 1) backrgb[0] = 0;
// DRAW STUFF IN THIS FUNCTION
}
@Override
public void dispose(GLAutoDrawable arg0)
{
// TODO Auto-generated method stub
}
@Override
public void keyTyped(KeyEvent e)
{
// TODO Auto-generated method stub
char key= e.getKeyChar();
System.out.printf("Key typed: %c\n", key);
}
@Override
public void keyPressed(KeyEvent e)
{
// TODO Auto-generated method stub
}
@Override
public void keyReleased(KeyEvent e)
{
// TODO Auto-generated method stub
}
/*
public void init(GLDrawable gLDrawable) {
final GL gl = glDrawable.getGL();
final GLU glu = glDrawable.getGLU();
gl.glMatrixMode(GL.GL_PROJECTION);
gl.glLoadIdentity();
glu.gluOrtho2D(-1.0f, 1.0f, -1.0f, 1.0f); // drawing square
gl.glMatrixMode(GL.GL_MODELVIEW);
gl.glLoadIdentity();
}*/
}
基本上，当我按下键盘上的键时，由于某种原因，"key typed" 永远不会输出，就好像它没有在听一样。我确定我的错误出在某个微不足道的地方，但我不确定它在哪里？
您需要确保 canvas 具有焦点，以便在那里接收输入事件。我无法从代码量中判断哪个 GUI 元素接收输入事件。也可以将侦听器添加到显示的框架和其他元素中。或者将焦点明确设置到 canvas（并确保它停留在那里）。
使用的方法叫JComponent.requestFocus（当然是API) and needs to be called after the elements are displayed
必须将 key listener 添加到框架 (canvas)。我会将 HelloOpenGL class 扩展为 Frame，如下所示：
public class HelloOpenGL extends Frame implements KeyListener{
public HelloOpenGL(){
addKeyListener(this); //this statement is missing from your code
setFocusable(true);
...
}
...
//Override KeyListener interface methods in this class
}
所以我会在 HelloOpenGL class 本身中进行关键事件处理，因为它是代表框架的那个，还要记住 @Andy Turner 所说的。我以这种方式尝试了一个程序，在我的情况下效果很好。